1. Field of the Invention
The present invention relates generally to a hinge device, and more particularly to a hinge for coupling two members in a device such as a portable radiotelephone comprising of two members that can be moved to folded and unfolded positions of the device with respect to each other about an axis, if so desired.
2. Description of the Related Art
A portable device such as a portable folder-type radiotelephone includes a keypad provided with a plurality of keys and a liquid crystal display. Usually, in the folder-type radiotelephone, the keypad is placed on one member while the liquid crystal display is placed on the other member. When the radiotelephone is not in use, the keypad or the liquid crystal display is moved to a folded position of the radiotelephone to face each other. Alternatively, when the radiotelephone is in use, the keypad or the liquid crystal display is moved to an unfolded position of the radiotelephone. It is the hinge that allows the two members to be coupled to each other and to be smoothly moved to the folded and unfolded positions.
The portable device such as the radiotelephone becomes smaller in size, but has more various implementing functions. This feature is especially notable in a radiotelephone based on standards known as IMT 2000. In addition to telephonic communication by the radiotelephone, a user can input short messages and send them by using a short message service (SMS), or view moving pictures. In some cases, the user may also use the Internet.
The conventional radiotelephone is usually unfolded or opened only at a single angle. The unfolded angle is determined through a preference survey. Recently, the radiotelephone has various functions provided to the user. The user's own preference regarding the unfolded angle varies according to each function. Therefore, it is improbable that the radiotelephone with the single unfolded angle would satisfy such user's demands.